I see a few people are having this issue, oddly mostly with Intel cards.
I have a Radeon HD 5430 card in mine and I use fglrx. I've seen more than my fair share of issues with AMD's buggy drivers. This time around my screen brightness settings only *kinda* work. Usually, if I hit the function keys, it pretty much just ignores me. Instead, I have to adjust the slider on the battery meter and THEN hit the function key and it'll adjust. It also sometimes doesn't adjust when I plug/unplug.
Anyways, I don't want to hijack someone else's thread but I'll be posting the same output that was used in this thread.
Here's lspci's vga line
here's my proc/cmdline
monsuco@EarthBound:~$ lspci -k | grep -iA3 VGA
02:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Park [Mobility Radeon HD 5430/5450/5470]
Subsystem: Dell Device 0457
Kernel driver in use: fglrx_pci
02:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Cedar HDMI Audio [Radeon HD 5400/6300 Series]
And here's my backlight interfaces
monsuco@EarthBound:~$ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-3.11.0-12-generic root=UUID=59e82249-d1d1-4593-9284-d7a0acd0779f ro quiet splash vt.handoff=7
And here's my pastebin
monsuco@EarthBound:~$ for i in /sys/class/backlight/*; do echo $i; cat $i/brightness; cat $i/actual_brightness; cat $i/max_brightness; done
This is probably as simple as blacklisting a single driver but I'm not an expert at these sorts of things.
I also still get occasional crashes (a bunch of random blocks on the screen, some of which blink). The brightness issues are new to 13.10 but I used to have it periodically crash for no reason and it still does that. I assume that's just fglrx being fickle but if there's something I need to do about that let me know. Who knows what happens when the new fglrx drivers or when Kubuntu switches to Wayland. Maybe that'll help, maybe that'll break a bunch of stuff.